Sweeper

ABSTRACT

The sweeper has a housing and wheels which support the housing for rolling movement on a surface to be swept. One or more brushes are rotatably mounted in the housing and have bristles which brush the surface to be swept. A drive train connects the single or several brushes with one or more of the wheels so that the respective brush or brushes will be rotated when the wheels turn. An energy storing arrangement in form of one or more springs is interposed in the drive train so that during the rolling movement energy will be stored which, when the rolling movement stops, will be dissipated and will serve to continue to rotate the one or more brushes for some time after the rolling movement of the wheels has stopped.

United States Patent [191 Liebscher SWEEPER [75] Inventor: Johannes Liebscher, Nassau (Lahn),

Germany [73] Assignee: Leifheit International Gunter Leifheit Gesellschaft mit Beschrankter Haftung, Nassau (Lahn), Germany [22] Filed: Oct. 1, 1974 [21] Appl. No.: 510,845

[30] Foreign Application Priority Data UNITED STATES PATENTS Liebscher 15/42 Sept. 23, 1975 Primary Examiner-Edward L. Roberts Attorney, Agent, or Firm-Michael S. Striker [57] ABSTRACT The sweeper has a housing and wheels which support the housing for rolling movement on a surface to be swept. One or more brushes are rotatably mounted in the housing and have bristles which brush the surface to be swept. A drive train connects the single or several brushes with one or more of the wheels so that the respective brush or brushes will be rotated when the wheels turn. An energy storing arrangement in form of one or more springs is interposed in the drive train so that during the rolling movement energy will be stored which, when the rolling movement stops, will be dissipated and will serve to continue to rotate the one or more brushes for some time after the rolling movement of the wheels has stopped.

14 Claims, 5 Drawing Figures S Patent Sept. 23,1975 Sheet 2 of2 3,906,575

SWEEPER BACKGROUND OF THE INVENTION i The present invention relates generally to a sweeper.

and more particularly. to a sweeper of the type that is used for sweeping surfaces of floors, carpets and the like.

Sweepers of this type are already well known from the art. They have brushes that rotate when a housing in which the brushes are journalled for rotation is pushed to-and-fro over a surface to be swept, such as a floor, a carpet, a rug or the like. The housing is supported on wheels and one or more brushes are provided for sweeping purposes, which brushes are connected in motion-receiving relationship with the wheels so that they turn when the wheels turn.

Basically, this type of sweeper is very satisfactory in everyday use. However, these sweepers suffer from a disadvantage which has been found very objectionable in many instances. In particular, since the motion which rotates the brush or brushes is transmitted from the respective wheels supporting the housing, it follows that as soon as the sweeper encounters an obstacle to further movement, for instance a piece of furniture, a base board or the like, it will not only be the movement of the housing that will stop but concomitantly therewith it will also be the rotation of the brush or brushes. This means that any dust or other particles which might inherently still be within the sweeping range of one or more of the brushes cannot be picked up, because the brushes will no longer rotate. This disadvantage is also encountered in the type of sweeper which, in addition to one or more of the conventional elongated brush rollers, also has one or more so-called edge brushes which are specifically designed to bring dust and other parti cles inwardly of the housing and within the sweeping range of the brush rollers, from marginal zones laterally of the housing that cannot be reached by the main brush rollers. The motion transmission to these edge brushes also stops when the movement of the sweeper drops over the surface to be swept, and hence they cannot perform their intended function under circumstances where the sweeper encounters an obstacle to its movement.

SUMMARY OF THE INVENTION Accordingly, it is an object of this invention to overcome the above-outlined disadvantages of the prior art.

More particularly, it is an object of this invention to provide an improved sweeper wherein the rotation of one or more of the brushes will continue for some time after the sweeper itself has stopped movement, that'is pets and the like, in a combination which comprises a housing, wheels supporting the housing for rolling movement on a surface to be swept, and a brush which is rotatablyrnounted in the housing and has portions which engage the surface to be swept. A drive train connected the brush with one of the wheels so that the brush is rotated in response to rolling movement of this one wheel.

Thus far, the features ,of the sweeper are already known from the prior art. In accordance with the pres ent invention, however, there is provided energy storing means which is interposed in the drive train to store energy during the rolling movement of the housing and the wheels, so that the brush continues to be rotated by dissipation of the, stored energy from the storing means, subsequent to termination of the rolling movement.

The energy storing means according to the present invention is a mechanical energy storing means and some of the energy used for moving the housing over the surface to be swept, usually in form of a push or pull exerted. by a user upon a handle that is connected with the housing, will be stored by the energy storing means which,lwhen the housing subsequently ceases its movement, for example due to encountering a piece of furniture or the like, will continue to drive the rotary brush until it has dissipated the stored energy.

Thus, the sweeper according to the present invention can now also be utilized for effectively sweeping surface areas which heretofore could not be so swept, for the reasons which were outlined earlier.

The novel features which are considered as characteristic for the invention are set forth in particular in the appended claims. The invention itself, however, both as to its construction and its method of operation, together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawing.

BRIEF DESCRIPTION OF THEVDRAWING DESCRIPTION OF THE PREFERRED EMBODIMENTS A first embodiment of the invention is illustrated in FIGS.- l-3. FIG. 1 is a bottom-plan view of a sweeper according to the present invention, having a housing 11 the underside of which is closed by a bottom wall 14 provided with various openings through which a brush roller 10 and support and drive wheels l2, 16 for the housing extend downwardly into contact with a surface (not shown) to be swept. The brush roller 10 is journalled for rotation in the housing about an axis which is not visible because it is concealed by the bottom wall 14. However, themanner in which the roller 10 is journalled is not of importance for an understanding of the present invention. When the brush roller 10 rotates, being driven for this purpose by motion-transmitting arrangements which transmit motion to it when and as the wheels 12 turn asthey roll over a surface to be swept, it picks up dust and other particles and deposits them inknown manner in a pair of upwardly open receptacles 13 located at opposite axial sides of the brush roller 10. These receptacles 13 are supported in known manner on the shafts on which the wheels 12 turn and which are also not visible because the presence of the housing 14 and of the receptacles 13. The motion transmitting arrangements between the wheels 12 and the brush roller are not visible because of the presence of the bottom wall 14, but are not essential for an understanding of the invention.

In addition to the brush roller 10 the sweeper in FIG. I is provided with so-called corner brushes or lateral brushes 15 which rotate about vertical axes and are substantially dish-shaped. The purpose of providing the brushes 15 is to draw in dust and the like from areas which are outwardly spaced beyond the housing 1 1 and which could not themselves be reached by the brush roller 10. The brushes 15 move this dirt inwardly beneath the housing 11 where it can be reached by the brush roller 10. Each of the brushes 15 is tumable about an upright axis as mentioned before, and is driven in rotation by a motion-transmitting drive train that is coupled with one of the surface-engaging wheels 16.

One embodiment of the drive train and the energy storing means associated therewith is illustrated in FIGS. 2 and 3. The wheel 16 is clearly visible in FIG. 2 and it will be seen that it is mounted on a shaft 18 which is journalled for rotation in an interior drive housing 17. The shaft 18 extends approximately normal to the direction of advancement of the housing 1 when the same is used for sweeping, that is when it is mvoed to-and-fro over a surface to be swept. The end portion of the shaft 18 which is remote from the wheel 16 is provided with or formed with a bevel gear 19 which meshes with another bevel gear 20 that is provided on or formed on a hollow shaft 21 which is tumably journalled in the housing 19 for rotation about an upright axis. The brush 15 (the embodiment will be explained with respect to only one of the two brushes 15 shown in FIG. 1, but is should be understood that each of the brushes is provided with a similar arrangement) has a substantially upright annulus of bristles which are secured in a carrier body 23 having a upwardly extending shaft portion 22 which extends through and is tumable in the hollow shaft 21.

The energy storing means in the embodiment of FIGS. 13 is designated in tote with reference numeral 24 and comprises two spiral springs 25 and 26 which act for energy storing and dissipating purposes in mutually opposite directions. In other words, when one of the springs 25 or 26 stores energy the other one dissipates it, and vice versa. The inner ends of the springs 25, 26 are connected to the shaft 21 and the outer ends are each connected to a connecting portion 27 or 28 of the body 23. FIG. 3 shows the manner in which the connection is effected, and from FIG. 2 it will be evident that the springs 25 and 26 are located in vertically spaced planes. Of course, the connection between the springs and the rotary components of the drive train could also be different from what is shown in FIGS. 2 and 3.

The upwardly directed surface of the body 23 is formed with a depression or recess 29 in which the springs 25, 26 are located. It will be appreciated that in dependence upon the direction in which the housing 1 is moved over the surface to be swept, and hence in dependence upon the direction in which the wheel 16 turns, one or the other of the springs 25, 26 will store energy as rotary motion is transmitted to it via the above-described drive train. As soon as the particular spring 25 or 26 is fully tensioned and can store no further energy, continued movement of the housing 1 in the previous direction transmits rotation to the body 23 and therefore to the brush having the annulus of bristles. The brush 15 then continues to rotate until the further movement of the housing 11 in the previous direction stops, for example when the direction of rotation of the housing is reversed or when the housing encounters an obstacle, such as a piece of furniture or the like. As soon as the housing stops its further movement, the rotation of the brush roller 10 also stops because the turning of the wheels 12 and 16 stops. If it were not for the energy storing means 24 of the present invention, the brushes 15 would also stop their rotation. However, as soon as the continued advancement of the housing 11 stops, the presence of the energy storing means 24 makes it possible for the brushes 15 to continue rotating, in that which ever one of the springs 25 or 26 has been tensioned to store energy, will now dissipate it energy and continue to turn the assoicated brush 15 until the energy dissipation is completed. The dirt that is swept up by the respective brush 15 is therefore moved inwardly beneath the housing 11 and, when subsequently the direction of advancement of the housing 11 is reversed, it can be picked up by the brush roller 10 which now again rotates.

In the illustrated embodiment each of the brushes 15 together with its drive train is mounted so that it can tilt about an axis 30 which extends transversely to the direction of the movement of the housing 11 when the device is moved to-and-fro over a surface to be swept. Because of the resistance resulting from the drive train and from friction between the bristles and the surface to be swept when the housing has come to a stop and its direction of advancement is being reversed, the respective brushes 15 with their housing 17 and the associated drive trains can tilt about the associated axis 30 and be inclined in a direction opposite to the one in which they were previously inclined. This means that a different portion of the annulus of bristles than previously is now in contact with the surface to be swept, thus assuring that it will always be such a portion of the bristle annulus in contact with the surface to be swept, which will sweep the dust inwardly of the beneath the housing 11 for engagement by the brush roller 10. Of course, it should be understood that the present invention is by no means limited to an arrangement wherein the brushes 15 are mounted for tilting movement about the axis 30.

FIGS. 4 and 5 show a further embodiment of the invention which is essentially the same as that in FIGS. l-3 and wherein like reference numerals identify like components.

InFIGS. 4 and 5, however, the energy storing means utilizes only a single spring 31 which is constructed as a torsion spring the opposite ends of which are connected with an engaging portion 32 of the shaft 21 and with an engaging portion 33 of the body 23, respectively. In addition, this embodiment comprises a radially projecting portion 34 on the shaft 21 which turns with the shaft 21 in a circular path, and an abutment 35 on the body 23 which extends into the path of movement of the projection 34.

In this embodiment the body 23 and therefore the bristle annulus of the brush 15 can freely turn with lost motion through almost a complete revolution with reference to'the shaftll before storage of energy begins. In the starting position, the portion 34 engages one side of the abutment 35 so that, when the housing 11 begins to move forwardly by being pushed .in such a' direction, there will be lost motion between the shaft 21 andthe body -23 until the portion 34 has completed almost a full revolution and engages the opposite side of the abutment 35 from the. one which: it previously contacted. During 'thislost motion period the :spring 31 constituting the energy storing means becomes increasingly tensioned and stores energy; Once the portion34 and the abutment 35 are in operative engagement-the energy stored in the spring 31 is fully retained; since no dissipation can occur, and there will now be a direct rotary motion transmission between the shaft 21 and the body 23, causing thelatterand'thus the brush '15 tbabe rotated until the wheel 16 stops when'the movement'of the housing 11 stops; 7

As in the embodiment of FIGS. 1-3, when themovement of the housing '11 and hence the turriing of the wheel 16 stops, the energy stored in 'the"pring31 will be dissipated, causing the respective brush to continue rotating until the abutment 35 has performed almost a complete revolution and engages the opposite side of the portion 34 from the one with which it was previously in contact. When the direction of turning movement of the wheel 16 and hence movement of the housing 11 is reversed, then the drive is initially transmitted via the portions 34 and and 35 directly to the body 23 without tensioning of the spring 31. Of course, this involves a limitation of the energy storing function to only one direction of advancement of the housing 1 and one direction of turning of the wheel 16. However, in most instances this will be of no disadvantageous consequence because as a rule turning of the brushes 15 after termination of the movement of the housing 1 is desired only in a forward end position upon reaching of an obstruction, such as a piece of furniture, whereas the continued rotation after stopping movement in the opposite direction is normally definitely desired.

The type of energy storing means utilized according to the present invention, as a mechanical storing means in form of springs, has the advantage of simplicity in that it eliminates the need for a complicated motor drive. Furthermore, it has the advantage that the storage of energy will be accomplished and completed during only a portion of the normal movement of the housing 11 in one or the other direction, and that subsequently all of the stored energy will be fully and completely dissipated by continued rotation of the respective brush 15. On the other hand, once the respective spring has been fully tensioned and energy is stored, further energy that is transmitted to the housing 11 in a sense moving it in one or the other direction will be directly and without any losses transmitted to the respective rotary brush and will continue to be so transmitted until the housing stops further movement, whereupon the stored energy will immediately begin to be dissipated. In the embodiment of FIG. 1, using the two separate springs acting in mutually opposite directions, the tensioning of one spring during the energystoring phase avoids unnecessary loosening of the other spring, since the spring being tensioned in effect acts upon completion of the tensioning as a rigid transmission element between the rotary components. The use of spiral springs in FIGS. 1-3, and their accommodation in a recess of the carrier body 23, permits the accommodation of the energystoringmeans in a small space and, in fact, without" requiring any additional space that is not already required by the presence of the body 23 itself. 3 w a The embodiment in FIGS. 3 and 4 is particularly suitable for certain applications, for example if the diameter of the brush 1 5 is relatively large sothat rotation of the brush 15'through less than one fullrevolution after the housing has come to a standstill, will suffice to obtain the desired brushing action.

It is of course conceivable to make various modifications in the illustrated embodiments without departing,

in any sense'from the concept :and intent of the present invention. The energy storing devices could be ar-' ranged in a manner other than illustrated, and at loca-' tions other than those shown. Different types'of springs could-be utilized, and the springs could be located be tween the wheel' 16 anda separate shaft corresponding to the shaft 18 and serving to drive the respective brush 15, or between the wheel 16 and for instance'theshaft' 21'."Als'o, the arrangementcould be usedfor driving not" only the brushes-'15, but instead"(orin'addition) th'e brush 10 or any other brush of the "sweeper. i

It will be understood that each of the elements described above, or two or more together, may also find a useful application in other types of constructions differing from the types described above.

While the invention has been illustrated and described as embodied in a sweeper, it is not intended to be limited to the details shown, since various modifications and structural changes may be made without departing in any way from the spirit of the present invention.

Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can, by applying current knowledge, readily adapt it for various applications, without omitting features that, from the standpoint of prior art, fairly constitute essential characteristics of the generic or specific aspects of this invention.

What is claimed as new and desired to be protected by letters patent is set forth in the appended claims:

1. In a sweeper, particularly for floors, carpets and the like, a combination comprising a housing; wheels supporting said housing for rolling movement on a surface to be swept; a brush rotatably mounted in said housing and having portions which engage the surface 'to be swept; a drive train connecting said brush with one of said wheels so that the brush is rotated in response to rolling movement of said one wheel; and energy storing means interposed in said drive train to store energy during said rolling movement, so that said brush continues to be rotated by dissipation of the stored energy from said storing means subsequent to termination of said rolling movement.

2. A combination as defined in claim 1, wherein said energy storing means comprises mechanical energy storing means.

3. A combination as defined in claim 1, wherein said energy storing means comprises spring means.

4. A combination as defined in claim 3, wherein said spring means comprises a single spring.

5. A combination as defined in claim 3, wherein said drive train comprises two rotary components in motion-transmitting relationship with one another; and wherein said spring means comprises a torsion spring cooperating with the respective rotary components so that the spring is tensioned in response to relative rotation of said rotary components.

6. A combination as defined in claim 5, wherein one of said rotary components carries said brush.

7. A combination as defined in claim further comprising a first abutment provided on and turable in a predetermined circular path with one of said rotary components, and a second abutment provided on the other of said rotary components and extending into said path for engagement withsaid first abutment upon competion of a partial relative revolution of said rotary components.

8. A combination as defined in claim 5, wherein said torsion spring is a helical spring having respective end portions which are connected with one and with the other of said rotary components, respectively.

9. A combination as defined in claim 1, wherein said drive train comprises two rotary components in motion-transmitting relation with one another; and wherein said energy storing means comprises a first spring connected with said components and storing energy when said one wheel turns in one direction, and a second spring also connected with said components and storing energy when said one wheel turns in an opposite direction.

10. A combination as defined in claim 9, wherein one of said components carries said brush.

1]. A combination as defined in claim 9, wherein said springs are spiral springs.

12. A combination as defined in claim 1, wherein said drive train comprises two relatively rotatable components, one of said components defining an axis of rotation for said brush and the other of said components being coaxial with and rotatable relative to said one component.

13. A combination as defined in claim 12, wherein said one component includes a carrier body for said brush, said body having a side facing upwardly away from the surface to be swept and provided with a depression in which said energy storing means is located.

14. A combination as defined in claim 13, wherein said brush has an annulus of bristles carried by said carrier body and having an upright orientation. 

1. In a sweeper, particularly for floors, carpets and the like, a combination comprising a housing; wheels supporting said housing for rolling movement on a surface to be swept; a brush rotatably mounted in said housing and having portions which engage the surface to be swept; a drive train connecting said brush with one of said wheels so that the brush is rotated in response to rolling movement of said one wheel; and energy storing means interposed in said drive train to store energy during said rolling movement, so that said brush continues to be rotated by dissipation of the stored energy from said storing means subsequent to termination of said rolling movement.
 2. A combination as defined in claim 1, wherein said energy storing means comprises mechanical energy storing means.
 3. A combination as defined in claim 1, wherein said energy storing means comprises spring means.
 4. A combination as defined in claim 3, wherein said spring means comprises a single spring.
 5. A combination as defined in claim 3, wherein said drive train comprises two rotary components in motion-transmitting relationship with one another; and wherein said spring means comprises a torsion spring cooperating with the respective rotary components so that the spring is tensioned in response to relative rotation of said rotary components.
 6. A combination as defined in claim 5, wherein one of said rotary components carries said brush.
 7. A combination as defined in claim 5; further comprising a first abutment provided on and turable in a predetermined circular path with one of said rotary components, and a second abutment provided on the other of said rotary components and extending into said path for engagement with said first abutment upon competion of a partial relative revolution of said rotary components.
 8. A combination as defined in claim 5, wherein said torsion spring is a helical spring having respective end portions which are connected with one and with the other of said rotary components, respectively.
 9. A combination as defined in claim 1, wherein said drive train comprises two rotary components in motion-transmitting relation with one another; and wherein said energy storing means comprises a first spring connected with said components and storing energy when said one wheel turns in one direction, and a second spring also connected with said components and storing energy when said one wheel turns in an opposite direction.
 10. A combination as defined in claim 9, wherein one of said components carries said brush.
 11. A combination as defined in claim 9, wherein said springs are spiral springs.
 12. A combination as defined in claim 1, wherein said drive train comprises two relatively rotatable components, one of said components defining an axis of rotation for said brush and the other of said components being coaxial with and rotatable relative to said one component.
 13. A combination as defined in claim 12, wherein said one component includes a carrier body for said brush, said body having a side facing upwardly away from the surface to be swept and provided with a depression in which said energy storing means is located.
 14. A combination as defined in claim 13, wherein said brush has an annulus of bristles carried by said carrier body and having an upright orientation. 